Insufficient amounts of essential dietary minerals can lead to poor development in children and severe medical problems in adults. For example, a diet deficient in calcium can result in abnormal skeletal growth and is associated with osteoporosis, particularly in elderly women. The fortification of food products with calcium and other minerals may help prevent disease and also contribute to better overall nutrition.
In order to successfully fortify foods and beverages, minerals must be in a form that does not adversely affect flavor, texture or appearance. This has been particularly difficult in the case of calcium which is often difficult to maintain in an aqueous solution and which sometimes imparts a chalky flavor to foods and beverages. Strategies for overcoming these problems have been reviewed by Weaver (Int'l Dairy J. 8:443–449 (1998)) and methods of making fortified beverages and supplements have been described in numerous publications (see e.g., U.S. Pat. Nos. 4,737,375; 6,106,874; and 5,075,999).
One approach that has been taken is to develop amino acid/mineral chelates that can be added to food products. In U.S. Pat. No. 4,830,716, a procedure is described in which amino acids are reacted with metals in a ratio of at least 2:1 to produce chelated minerals. U.S. Pat. No. 5,516,925 discloses metal/amino acid chelates in which sufficient ligand is present to provide ionic, covalent and coordinate bonds equal to the coordination number of the metal ion while maintaining charge balance. Although many of the procedures that have been described appear to be concerned with the formation of stable chelates, metastable complexes of calcium citrate and malate have also been described (U.S. Pat. No. 5,186,965). Further improvements in methods of making mineral complexes will ultimately lead to food products of higher nutritional value.